Modern networks offer users an increasing array of capabilities to communicate with each other and with automated systems. For example, telephone networks provide ubiquitous service throughout developed countries, allowing people to talk to each other almost anywhere. The development of public wireless telephone networks (e.g. cellular and PCS networks) has enhanced this communication ability by adding the convenience of almost limitless mobility. The Internet and packet-based data communications now enable rapid communication of a vast array of data, such as e-mail, web pages and multi-media content. Advanced versions of wireless networks extend the concept of wireless mobility to support similar data communication applications.
In addition to the traditional voice telephone-type communications and the common data communications such as e-mail and web browsing, such networks have been used for a variety of communications applications that entail high-volumes of message or call traffic in a very short period of time. Events occurring in such communication applications, which generate such high-volumes of message or call traffic in a very short period of time, are referred to herein as mass communication events. A common example of such an application involves voting, and an event in a voting application would be the occurrence of a high volume of voting traffic at a time called for a vote.
Mass traffic events, such as voting, first utilized the public switched telephone network. More recently, however, such communication applications have been extended to mobile wireless communication networks, to allow participation by mobile network subscribers using their increasingly ubiquitous wireless mobile stations. For example, Published US Patent Application 2003/0100321 to Rao et al. entitled “Instantaneous polling utilizing a message service mobile phone network,” teaches use of a wireless short message service (SMS) for polling or the like.
The traffic generated by such a mass communication event poses problems for a mobile wireless communication network. During mass end-user messaging, such as voting for the “American Idol” program or a sports event voting, very large numbers of subscriber generated calls or short messages are transmitted via the wireless network in a very short time interval. To handle this mass traffic, a wireless network would need to be engineered to support an appropriate level of peak loading, which is costly or impractical. There is a need to mitigate the impact of such a mass communication event on the resources of the mobile wireless communication network.
Efforts to solve congestion problems due to mass call-in events through the landline telephone network have focused on network based control of the call flows. For example, U.S. Pat. No. 6,259,776 to Hunt, entitled “System for controlling telecommunication overload traffic,” teaches overload control by network control of call gapping. An overload control function measures the period of time taken to handle a call switching request. If the time taken exceeds a pre-determined quality of service threshold, the control implements a call gapping function, which modifies the gapping period such that requests to effect calls to particular destinations are spaced. Any call arriving at a switching point prior to expiration of the gap period is automatically rejected by the local control processor.
Published US Patent Application 2002/0159576 to Anthony, entitled “Method for overload control in a telecommunications network and apparatus therefor,” discloses a technique for suppressing overload in a UMTS type mobile network. The Anthony methodology entails receiving a signal that calls sent to a target node are being rejected. In response, the network reduces the rate of calls it sends to the target node.
Published US Patent Application 2004/0022366 to Ferguson et al., entitled “Apparatus, and an associated method, for detecting a mass call event and for ameliorating the effects thereof,” teaches use of a detector to monitor call attempts. When more than a selected level of call attempts are made to a particular called station, within a selected period, a mass call event is considered to have occurred. A notifier initiates notification of other network elements in the telephonic network, and the rate at which call connections are permitted with the called station is limited during the duration of the mass call event.
Such network-centric control of the calls, by call gapping or the like, are difficult to implement in a mobile wireless network. Also, many such solutions delay a user's call for some period which is apparent to the user, by extended gaping or by actually blocking calls through the network. If the user perceived delay is extensive, or the network rejects the user's message or call too many times, the user may become dissatisfied with the experience and refrain from future participation, which diminishes the effectiveness and commercial value of the network-based voting application. Hence, the landline solutions have not adequately addressed the needs, particularly of the wireless network domain.
For a mobile network, US Patent Application Publication 2001/0005670 to Lahtinen, entitled “Method and system for the control of voting by telephone,” teaches use of a polling server to authorize a predetermined initial proportion of the mobile stations to concurrently transmit a vote. The polling server sends the voting authorizations to the authorized mobile stations over a control channel. A voting application stored in or associated with each mobile station monitors the control channel and enables transmission of a vote only after the authorization has been received by that mobile station. Lahtinen suggests that this combination of server authorization and mobile station control application accommodates and assures the staggered transmission of votes in a telephonic poll, in order to avoid overloading of the network. Although this may reduce the peak load somewhat, the need to authorize stations to transmit actually results in overhead traffic during the event, added to the already heavy traffic load caused by the event.